<?php
/**
 * Zend Framework
 *
 * LICENSE
 *
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 *
 * @category   Zend
 * @package    Zend_Mail
 * @subpackage Storage
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 * @version    $Id: Mbox.php 18951 2009-11-12 16:26:19Z alexander $
 */


/**
 * @see Zend_Loader
 * May be used in constructor, but commented out for now
 */
// require_once 'Zend/Loader.php';

/**
 * @see Zend_Mail_Storage_Abstract
 */
require_once 'Zend/Mail/Storage/Abstract.php';

/**
 * @see Zend_Mail_Message_File
 */
require_once 'Zend/Mail/Message/File.php';


/**
 * @category   Zend
 * @package    Zend_Mail
 * @subpackage Storage
 * @copyright  Copyright (c) 2005-2009 Zend Technologies USA Inc. (http://www.zend.com)
 * @license    http://framework.zend.com/license/new-bsd     New BSD License
 */
class Zend_Mail_Storage_Mbox extends Zend_Mail_Storage_Abstract
{
	/**
	 * file handle to mbox file
	 * @var null|resource
	 */
	protected $_fh;

	/**
	 * filename of mbox file for __wakeup
	 * @var string
	 */
	protected $_filename;

	/**
	 * modification date of mbox file for __wakeup
	 * @var int
	 */
	protected $_filemtime;

	/**
	 * start and end position of messages as array('start' => start, 'seperator' => headersep, 'end' => end)
	 * @var array
	 */
	protected $_positions;

	/**
	 * used message class, change it in an extened class to extend the returned message class
	 * @var string
	 */
	protected $_messageClass = 'Zend_Mail_Message_File';

	/**
	 * Count messages all messages in current box
	 *
	 * @return int number of messages
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function countMessages()
	{
		return count($this->_positions);
	}


	/**
	 * Get a list of messages with number and size
	 *
	 * @param  int|null $id  number of message or null for all messages
	 * @return int|array size of given message of list with all messages as array(num => size)
	 */
	public function getSize($id = 0)
	{
		if ($id) {
			$pos = $this->_positions[$id - 1];
			return $pos['end'] - $pos['start'];
		}

		$result = array();
		foreach ($this->_positions as $num => $pos) {
			$result[$num + 1] = $pos['end'] - $pos['start'];
		}

		return $result;
	}


	/**
	 * Get positions for mail message or throw exeption if id is invalid
	 *
	 * @param int $id number of message
	 * @return array positions as in _positions
	 * @throws Zend_Mail_Storage_Exception
	 */
	protected function _getPos($id)
	{
		if (!isset($this->_positions[$id - 1])) {
			/**
			 * @see Zend_Mail_Storage_Exception
			 */
			require_once 'Zend/Mail/Storage/Exception.php';
			throw new Zend_Mail_Storage_Exception('id does not exist');
		}

		return $this->_positions[$id - 1];
	}


	/**
	 * Fetch a message
	 *
	 * @param  int $id number of message
	 * @return Zend_Mail_Message_File
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function getMessage($id)
	{
		// TODO that's ugly, would be better to let the message class decide
		if (strtolower($this->_messageClass) == 'zend_mail_message_file' || is_subclass_of($this->_messageClass, 'zend_mail_message_file')) {
			// TODO top/body lines
			$messagePos = $this->_getPos($id);
			return new $this->_messageClass(array('file' => $this->_fh, 'startPos' => $messagePos['start'],
                                                  'endPos' => $messagePos['end']));
		}

		$bodyLines = 0; // TODO: need a way to change that

		$message = $this->getRawHeader($id);
		// file pointer is after headers now
		if ($bodyLines) {
			$message .= "\n";
			while ($bodyLines-- && ftell($this->_fh) < $this->_positions[$id - 1]['end']) {
				$message .= fgets($this->_fh);
			}
		}

		return new $this->_messageClass(array('handler' => $this, 'id' => $id, 'headers' => $message));
	}

	/*
	 * Get raw header of message or part
	 *
	 * @param  int               $id       number of message
	 * @param  null|array|string $part     path to part or null for messsage header
	 * @param  int               $topLines include this many lines with header (after an empty line)
	 * @return string raw header
	 * @throws Zend_Mail_Protocol_Exception
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function getRawHeader($id, $part = null, $topLines = 0)
	{
		if ($part !== null) {
			// TODO: implement
			/**
			* @see Zend_Mail_Storage_Exception
			*/
			require_once 'Zend/Mail/Storage/Exception.php';
			throw new Zend_Mail_Storage_Exception('not implemented');
		}
		$messagePos = $this->_getPos($id);
		// TODO: toplines
		return stream_get_contents($this->_fh, $messagePos['separator'] - $messagePos['start'], $messagePos['start']);
	}

	/*
	 * Get raw content of message or part
	 *
	 * @param  int               $id   number of message
	 * @param  null|array|string $part path to part or null for messsage content
	 * @return string raw content
	 * @throws Zend_Mail_Protocol_Exception
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function getRawContent($id, $part = null)
	{
		if ($part !== null) {
			// TODO: implement
			/**
			* @see Zend_Mail_Storage_Exception
			*/
			require_once 'Zend/Mail/Storage/Exception.php';
			throw new Zend_Mail_Storage_Exception('not implemented');
		}
		$messagePos = $this->_getPos($id);
		return stream_get_contents($this->_fh, $messagePos['end'] - $messagePos['separator'], $messagePos['separator']);
	}

	/**
	 * Create instance with parameters
	 * Supported parameters are:
	 *   - filename filename of mbox file
	 *
	 * @param  $params array mail reader specific parameters
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function __construct($params)
	{
		if (is_array($params)) {
			$params = (object)$params;
		}

		if (!isset($params->filename) /* || Zend_Loader::isReadable($params['filename']) */) {
			/**
			 * @see Zend_Mail_Storage_Exception
			 */
			require_once 'Zend/Mail/Storage/Exception.php';
			throw new Zend_Mail_Storage_Exception('no valid filename given in params');
		}

		$this->_openMboxFile($params->filename);
		$this->_has['top']      = true;
		$this->_has['uniqueid'] = false;
	}

	/**
	 * check if given file is a mbox file
	 *
	 * if $file is a resource its file pointer is moved after the first line
	 *
	 * @param  resource|string $file stream resource of name of file
	 * @param  bool $fileIsString file is string or resource
	 * @return bool file is mbox file
	 */
	protected function _isMboxFile($file, $fileIsString = true)
	{
		if ($fileIsString) {
			$file = @fopen($file, 'r');
			if (!$file) {
				return false;
			}
		} else {
			fseek($file, 0);
		}

		$result = false;

		$line = fgets($file);
		if (strpos($line, 'From ') === 0) {
			$result = true;
		}

		if ($fileIsString) {
			@fclose($file);
		}

		return $result;
	}

	/**
	 * open given file as current mbox file
	 *
	 * @param  string $filename filename of mbox file
	 * @return null
	 * @throws Zend_Mail_Storage_Exception
	 */
	protected function _openMboxFile($filename)
	{
		if ($this->_fh) {
			$this->close();
		}

		$this->_fh = @fopen($filename, 'r');
		if (!$this->_fh) {
			/**
			 * @see Zend_Mail_Storage_Exception
			 */
			require_once 'Zend/Mail/Storage/Exception.php';
			throw new Zend_Mail_Storage_Exception('cannot open mbox file');
		}
		$this->_filename = $filename;
		$this->_filemtime = filemtime($this->_filename);

		if (!$this->_isMboxFile($this->_fh, false)) {
			@fclose($this->_fh);
			/**
			 * @see Zend_Mail_Storage_Exception
			 */
			require_once 'Zend/Mail/Storage/Exception.php';
			throw new Zend_Mail_Storage_Exception('file is not a valid mbox format');
		}

		$messagePos = array('start' => ftell($this->_fh), 'separator' => 0, 'end' => 0);
		while (($line = fgets($this->_fh)) !== false) {
			if (strpos($line, 'From ') === 0) {
				$messagePos['end'] = ftell($this->_fh) - strlen($line) - 2; // + newline
				if (!$messagePos['separator']) {
					$messagePos['separator'] = $messagePos['end'];
				}
				$this->_positions[] = $messagePos;
				$messagePos = array('start' => ftell($this->_fh), 'separator' => 0, 'end' => 0);
			}
			if (!$messagePos['separator'] && !trim($line)) {
				$messagePos['separator'] = ftell($this->_fh);
			}
		}

		$messagePos['end'] = ftell($this->_fh);
		if (!$messagePos['separator']) {
			$messagePos['separator'] = $messagePos['end'];
		}
		$this->_positions[] = $messagePos;
	}

	/**
	 * Close resource for mail lib. If you need to control, when the resource
	 * is closed. Otherwise the destructor would call this.
	 *
	 * @return void
	 */
	public function close()
	{
		@fclose($this->_fh);
		$this->_positions = array();
	}


	/**
	 * Waste some CPU cycles doing nothing.
	 *
	 * @return void
	 */
	public function noop()
	{
		return true;
	}


	/**
	 * stub for not supported message deletion
	 *
	 * @return null
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function removeMessage($id)
	{
		/**
		 * @see Zend_Mail_Storage_Exception
		 */
		require_once 'Zend/Mail/Storage/Exception.php';
		throw new Zend_Mail_Storage_Exception('mbox is read-only');
	}

	/**
	 * get unique id for one or all messages
	 *
	 * Mbox does not support unique ids (yet) - it's always the same as the message number.
	 * That shouldn't be a problem, because we can't change mbox files. Therefor the message
	 * number is save enough.
	 *
	 * @param int|null $id message number
	 * @return array|string message number for given message or all messages as array
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function getUniqueId($id = null)
	{
		if ($id) {
			// check if id exists
			$this->_getPos($id);
			return $id;
		}

		$range = range(1, $this->countMessages());
		return array_combine($range, $range);
	}

	/**
	 * get a message number from a unique id
	 *
	 * I.e. if you have a webmailer that supports deleting messages you should use unique ids
	 * as parameter and use this method to translate it to message number right before calling removeMessage()
	 *
	 * @param string $id unique id
	 * @return int message number
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function getNumberByUniqueId($id)
	{
		// check if id exists
		$this->_getPos($id);
		return $id;
	}

	/**
	 * magic method for serialize()
	 *
	 * with this method you can cache the mbox class
	 *
	 * @return array name of variables
	 */
	public function __sleep()
	{
		return array('_filename', '_positions', '_filemtime');
	}

	/**
	 * magic method for unserialize()
	 *
	 * with this method you can cache the mbox class
	 * for cache validation the mtime of the mbox file is used
	 *
	 * @return null
	 * @throws Zend_Mail_Storage_Exception
	 */
	public function __wakeup()
	{
		if ($this->_filemtime != @filemtime($this->_filename)) {
			$this->close();
			$this->_openMboxFile($this->_filename);
		} else {
			$this->_fh = @fopen($this->_filename, 'r');
			if (!$this->_fh) {
				/**
				 * @see Zend_Mail_Storage_Exception
				 */
				require_once 'Zend/Mail/Storage/Exception.php';
				throw new Zend_Mail_Storage_Exception('cannot open mbox file');
			}
		}
	}

}
